Year	Years
1970	0.3
1971	0.31
1972	0.33
1973	0.34
1974	0.35
1975	0.36
1976	0.37
1977	0.39
1978	0.4
1979	0.41
1980	0.43
1981	0.44
1982	0.46
1983	0.48
1984	0.49
1985	0.51
1986	0.53
1987	0.55
1988	0.57
1989	0.59
1990	0.61
1991	0.63
1992	0.65
1993	0.68
1994	0.7
1995	0.73
1996	0.76
1997	0.79
1998	0.82
1999	0.85
2000	0.88
2001	0.91
2002	0.94
2003	0.97
2004	1.01
2005	1.04
2006	1.08
2007	1.12
2008	1.15
2009	1.19
2010	1.23
2011	1.27
2012	1.32
2013	1.36
2014	1.41
2015	1.45